I installed a 2.6.20.1 vanilla kernel today to prepare my system for a patch
from Tejun Heo. Under the unpatched vanilla 2.6.20.1 kernel NCQ is enabled at
boot time and the kernel bug (messages) described above have vanished. The
problem might be related to the JMB363 actually rather than the Intel ICH8R.
Reference: http://lkml.org/lkml/2007/2/21/11